Air-cooled cylinder head for internal-combustion engines



Oct. l2, 1954 E FLA-rz ET AL 2,691,366

-COMBUSTION ENGINES AIR-COOLED CYLINDER HEAD FOR INTERNAL 2 shets-sheet1 Filed Oct. 2. 1951 .ZY/[Maes Hafl- Jose/f H'vel Raw; 47M? llil.

Oct. 12, 1954 E. FLATz ETAL 2,691,366

DER HEAD FOR INTERNAL-COMBUSTION ENGINES AIR-COOLED CYLIN 2 Sheets-Sheet2 Filed Oct. 2 1951 Patented Oct. 12, 1954 AIR-COOLED CYLINDER HEAD FORINTERNAL-CGMBUSTION ENGINES Emil Flatz, Bergisch-Gladbach, and JosefHvel,

Koln-Bruck, Germany,

Humboldt-Deutz Aktien many assignors to Klcknergesellschaft, Koln, Ger-Application October 2, 1951, Serial No. 249,243

Claims priority, application Germany October 28, 1950 6 Claims. (Cl.12S-411.69)

The present invention relates to internal combustion engines and, moreparticularly, to air cooled cylinder heads for internal combustionengines.

While not specifically limited to, the present invention is ofparticular advantage for such cylinder heads of. internal combustionengines which are provided with two passages of the inlet and/or outletof a gaseous medium, one of said passages leading upwardly, While valves.are arranged, one behind the other, when looking in the longitudinaldirection of the engine, and While above the cylinder head, there isarranged a cup for receiving the rocker arms for actuating said valves.

As is well known, with an air cooled cylinder head for internalcombustion engines, the cooling of that area which is located betweenthe valves presents considerable difculties. rThis is due to the factthat it is rather difficult to bring e from the outside suciently largequantities of cooling air to the said area. The passages extending fromsaid valves impede the now of cooling air considerably. In order toobtain more favorable conditions for the passage of cooling air, it hasbeen attempted to run the pasasge in diierent directions toward theoutside. Thus, it has been suggested to run the outlet passage towardthe side, and to run the inlet passage toward the top through the cup ontop of thc cylinder head which cup for actuating the valves. Such anarrangement, however, has not proved successful for reasons which willsubsequently appear.

The passing of the inlet passage through the cup makes it necessary forreasons connected with the casting operation proper, to place the cup asseparate piece upon the cylinder head. Tests with air cooled cylinderheads having mounted thereon a separate cup for receiving the rockerarms have proved that it is extremely dihicult, if not impossible, forany practical length of time to connect such cup in an oil leak-proofmanner with the cylinder head. It cannot be prevented that after arelatively short receives the rocker arms time, the oil intended andnecessary for the lubrication of the rocker arms seeps throughdownwardly and wets the cylinder head. As a direct result thereof, theheat transfer from the cylinder head to the cooling air will bedecreased. Furthermore, the impurities present in the cooling air remainstuck atthe oil wetted portions of the cylinder head andgradually buildup a thick insulating layer preventing a proper heat exchange.

v with the cylinder head, thereby preventing any lubricating oil frompassing through the cup toward the cylinder head.

It is still another object oi this invention, to provide an air cooledcylinder head of the type mentioned above, which will materiallyincrease the cross section for the passage of the coolingr air betweenthe valves.

It is also an object of this invention to provide an air cooled cylinderhead for use in connection with internal combustion engines, in which apassage extending from one of its valves toward the top of the cylinderhead is arranged so that it can easily be cast together with thecylinder head while oiering only a minimum of resistance to the mediumpassing through said passage.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection With theaccompanying drawings in which:

Fig. l represents a vertical section through a cylinder head accordingtothe present invention, the section being taken along the verticalplane passing through the valves.

Fig. 2 is a transverse section along the line II-II of Fig. 1.

Fig. 3 is a top view of the cylinder head of Fig. 1.

Fig. 4. is a transverse section similar to that of `Fig. 2 but slightlymodined with regard to the latter.

Fig. 5 is a transverse section through still another modified cylinderhead according to the present invention.

General arrangement As mentioned above, the present invention concernsan air cooled cylinder head with two passages for the inlet and/oroutlet of a gaseous medium, which passages are controlled by valvesarranged one behind the other, when looking in longitudinal direction ofthe engine, while on top of the cylinder head there is provided a cupfor receiving the rocker arms adapted to actuate the valves. Accordingto the present invention, one of the said passages extends from one ofthe valves to the top` of the cylinder head in such a manner that itsmouth at the top of the cylinder head is located outside the cup.

According to a preferred embodiment of the invention, the passageleading to the top of the cylinder head of one cylinder of amulti-cylinder engine is so arranged that its upper portion lies over aportion of the adjacent cylinder head. In order that in such anarrangement the cylinder heads may be uniformly constructed and thecylinders be arranged as close together as possible, that cooling iinportion of one cylinder head which is adjacent to the upper portion ofthe upwardly leading passage of the adjacent cylinder head, is providedwith a recess or cut-out or is reduced in height.

In view of the arrangement of the upwardly leading passage in the mannerjust mentioned, it is possible to cast the cup with the cylinder head asone integral piece.

In order further to improve cylinder head when the latter is to be usedin connection with an internal combustion engine having a cam shaft inthe crank case and push rods between the cam shaft and the rocker arms,

the second passage in the cylinder head is so arranged that its mouth islocated on the longitudinal side of the engine, while the push rods arearranged on each side of said mouth respectively.

According to a modification oi the arrangement set forth in thepreceding paragraph, the mouth of the second passage may be located onthe longitudinal side cf the engine but laterally of the centralcylinder head plane which is substantially transverse while both pushrods are located on one and the same side of said last mentioned mouth.In this instance, the push rods are preferably located symmetrically tothe central transverse plane of the cylinder head.

While in most instances the passage leading upwardly to the top of thecylinder head serves as inlet passage, it is to be understood that theupwardly leading passage may also serve as outlet passage.

As is well known, there are two stroke cycle engines having a cylinderhead with two valves for controlling the discharge. Thus, with this typeof internal combustion engines, the two passages arranged in thecylinder head are discharge passages. It is obvious that with such twostroke cycle engines, the cooling of that area ci the cylinder headwhich is located between the discharge valves is even more diicult sothat the present invention is of particular importance for this type oftwo stroke cycle internal combustion engines.

Structural arrangement Referring now to the drawings in detail andFigures 1 to 3 thereof in particular, the structure shown thereincomprises a cylinder head i provided with a discharge valve 2 and anintake valve 3. From the discharge valve 2 there extends a dischargepassage Il leading to the outside of the cylinder head and having itsmouth located on the longitudinal side of the engine to which thecylinder head pertains. Another passage 5, in this particular instancean intake passage, extends from the intake valve 3 likewise to theoutside of the cylinder head l but has its mouth on the top side of thecylinder head. As will be seen from Fig. l, the upper end portion of theypassage 5 is located laterally of the cup 6 which latter has been castas an integral piece with the cylinder head. The cup 6 serves thecooling of the to said longitudinal side, i;

4 for receiving the rocker arms l' (Fig. 3) intended for actuating thevalves 2 and 3. In addition to the valves 2 and 3 and the passa-gesl!and 5, the cylinder head also comprises a main combustion chamber sconnected by a throat with a combustion chamber 9.

As will be clear, particularly from Figures 1 and 2, the new arrangementof the intake passage creates between the two valves 2 and 3 amaterially increased cross section for the passage o cooling air.Therefore, the invention makes it possible above the web I0, which is1ocated between valves 2 and 3, to provide a greater number of coolingiins Il than heretofore possible, which fins will receive the heat fromthe web IB and transfer the thus received heat to the cooling air whichcarries it away.

In order to avoid that due to the new arrangement of the passage 5,particularly the upper end thereof, the distance between two adjacentcylinders has to be enlarged, the upper end of the passage 5 is soarranged that it lies over a portion of the adjacent cylinder head i2,while the cooling iins of the latter are correspondingly recessed orshortened so as not to interfere with the passage 5. For the sake ofsimplicity and uniformity, preferably all cylinders of the internalcombustion engine have their corresponding cooling fins similarlyrecessed or shortened.

With the cylinder head according to Figures l to 3, the orifice of thedischarge passage d is located in the central vertical transverse planeof the cylinder head l. This makes it possible respectively to arrangethe push rods i5 at both sides of the passage fi and symmetrically withregard to the said central vertical transverse plane of the cylinderhead. The push rods I5 are actuated in the usual manner by a cam shaftlocated in the crank case of the engine (not hshown in the drawings). v

According to the modiiications shown in Figures a and 5, a furtherimprovement of the cooling effect of the air passing between the valves2 and 3, and also a simpler construction of the cooling fins l l betweenthe valves can lne-obtained when the orice of the passage t is locatedlaterally of the above mentioned vertical central transverse plane ofthe cylinder head. In such an instance, a straight passage for thecooling air is obtained, and the cooling fins can be made straight.

According to Fig. 4, the discharge passage t is bent oif toward one sideto such an extent that its orifice is located outside the symmetricallyarranged push rods lli. One of the connecting screws It of the cylinderhead is located inside the discharge passage.

According to Figure 5, the discharge passage i is passed by theconnecting screw il'. The push rods l5, however, are again arranged atboth sides of the discharge passage l but like the latter are locatedlaterally of the above mentioned central vertical transverse plane.

It is, of course, understood that the present invention is, by no means,limited to the particular constructions shown in the drawings but aisocomprises any modifications within the scope ci the appended claims.

What we claim is:

l. An air cooled cylinder head arrangement for a multi-cylinder internalcombustion engine, which comprises in combination, a nrst cylinder head,a second cylinder head in line with said first cylinder head, coolingIins respectively connected to the outside of said cylinder heads, eachof said cylinder heads having arranged therein rst valve passages meansadapted to be controlled by a Valve, and also second valve passage meansadapted to be controlled by another valve, rst cup means arranged on topof said rst cylinder head and integral therewith, second cup meansarranged on top of said second cylinder head and integral therewith,each of said cup means being adapted to receive valve actuating rockerarms, and channel means respectively arranged in each of said cylinderheads and extending from one of said valve passage means to the top ofthe respective cylinder head and outside and laterally of the adjacentcup means, the upper end portion of the channel means pertaining to saidrst cylinder head extending over a portion of said second cylinder head.

2. An air cooled cylinder head arrangement fora multi-cylinder internalcombustion engine,

'which comprises in combination, a rst cylinder head, a second cylinderhead in line with said rst cylinder head, cooling ns respectivelyconnected to the outside of said cylinder heads, each of said cylinderheads having arranged therein rst valve passage means adapted to becontrolled by a valve, and also second valve passage means adapted to becontrolled by another valve, first cup means arranged on top of said`iirst cylinder head, second cup means arranged on top of said secondcylinder head, each of said cup means being adapted to receive valveactuating rocker arms, and channel means respectively arranged in eachof said cylinder heads and extending from one of said valve passagemeans to the top of the respective cylinder head and outside theadjacent cup means, the upper end portion of the channel meanspertaining to said rst cylinder head protruding beyond a portion of saidsecond cylinder head, and those iins of said second cylinder head whichare adjacent said last mentioned upper end portion being of such sizeand shape as not to interfere with said last mentioned upper endportion.

3. In combination for use in connection with an internal combustionengine, a cylinder head, cooling ns connected to the outside of saidcylinder head, an intake passage arranged Within said cylinder head andadapted to be controlled by an intake valve, an exhaust passage arrangedwithin said cylinder head and adapted to be controlled by an exhaustvalve, cup means integral with the top of said cylinder head forreceiving y valve actuating rocker arms, inlet channel means extendingfrom said intake Valve passage to and having its mouth located in thetop surface of said cylinder head and outside said cup means, andexhaust channel means extending from said exhaust passage to and havingits mouth protrude beyond one of those sides of said cylinder head whichform the longitudinal sides of the engine, the axis of the outer end ofsaid exhaust passage being located laterally of the vertical centralplane passing through the cylinder head and being substantiallyperpendicular to the longitudinal direction of the engine, andadditional cooling fins between said inlet and said outlet channel meansand integral with said cylinder head.

4. In combination in a cylinder head arrangement for use in connectionwith an internal combustion engine, a cylinder head, cooling nsconnected to the outside of said cylinder head, a first valve passagearranged Within said cylinder head and adapted to be controlled by a rstvalve, a second valve passage ararnged Within said cylinder head andadapted to be controlled by a second valve, cup means integral with thetopk of said cylinder head for receiving valve actuating rocker arms,first channel means extending from said rst valve passage to the topsurface of said cylin` der head and having its mouth located in said topsurface and outside said cup means, second channel means extending fromsaid second valve passage to and having its mouth protruding beyond oneof those sides of said cylinder head which form the longitudinal sidesof the engine, push rods arranged at both sides of the outer end of saidsecond channel means for actuating said rocker arms, and additionalcooling fins extending between said push rods.

5. In combination in a cylinder head arrangement for use in connectionwith an internal comhead outside said cup means, second channel` meansextending from said second valve passage to one of those sides of saidcylinder head which form the longitudinal sides of the engine, and apair of push rods arranged at one and the same side of the outer end 'ofsaid second channel means for actuating said rocker arms.

6. In combination for use in connection with an internal combustionengine, a cylinder head, cooling ns connected tothe outside of saidcylinder head, an intake passage arranged within said cylinder head andadapted to be controlled by an intake valve, an exhaust passage arrangedwithin said cylinder head and adapted to be controlled by an exhaustvalve, cup means integral with the top of said cylinder head forreceiving valve actuating rocker arms, inlet channel means extendingfrom said intake valve passage to the top of said cylinder head outsidesaid cup means, and exhaust channel means extending from said exhaustpassage to one of those sides of said cylinder head which form thelongitudinal sides of the engine, the axis of the outer end of saidexhaust passage being laterally spaced from that vertical central plane,Which passes through the cylinder head and is substantiallyperpendicular to the longitudinal direction of the engine, and a firstand second push rod for actuating said rocker arms, said nrst push rodbeing arranged between said vertical plane and the outlet of saidexhaust channel means, and both of said push rods being arrangedsymmetrically with regard to said vertical central plane.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,506,950 Smith Sept. 2, 1924 1,884,321 Smith Oct. 25, 19322,199,619 Daub May 7, 1940 FOREIGN PATENTS Number Country Date 346,683Germany Jan. 6, 1922 900,899 France Oct. 23, 1944 574,684 Great BritainJan. 16, 1946

